There has been known a lighting device that includes first light emitting diodes (LEDs) and second LEDs, where each of the first LEDs is configured to emit light with a first correlated color temperature and each of the second LEDs is configured to emit light with a second correlated color temperature (for example, see JP2013-131393A, hereinafter referred to as “Document 1”). The lighting device of Document 1 includes a data storage device that stores, in a data table, values of a first drive current (current supplied to the first LEDs) and a second drive current (current supplied to the second LEDs) which are predefined to be associated with light intensity and correlated color temperatures of the lighting device. The lighting device of Document 1 further includes a first and second drive circuits. The first drive circuit is configured to: generate, when a value of a first drive current is smaller than a predefined specific current value, the first drive current by pulse width modulating a DC current of which magnitude is the specific current value; and generate, when a value of a first drive current is larger than the specific current value, the first drive current of a DC current. Similarly, the second drive circuit is configured to: generate, when a value of a second drive current is smaller than a predefined specific current value, the second drive current by pulse width modulating a DC current of which magnitude is the specific current value; and generate, when a value of a second drive current is larger than the specific current value, the second drive current of a DC current. Further, Document 1 discloses an example in which the number of first LEDs is the same as the number of second LEDs. In this conventional lighting device, by adjusting relative lighting conditions of the first LEDs and the second LEDs, the light color can be changed in a range from warm color to cool color and also the light intensity can be changed with a fixed correlated color temperature.
However, in the lighting device disclosed in Document 1, both the first drive current and the second drive current should be changed in order to change the light intensity and the light color.